o eliminate widespread on-stack mbuf use for bpf by introducing

  a new bpf_mtap2 routine that does the right thing for an mbuf
  and a variable-length chunk of data that should be prepended.
o while we're sweeping the drivers, use u_int32_t uniformly when
  when prepending the address family (several places were assuming
  sizeof(int) was 4)
o return M_ASSERTVALID to BPF_MTAP* now that all stack-allocated
  mbufs have been eliminated; this may better be moved to the bpf
  routines

Reviewed by:	arch@ and several others

1 files changed, 1 insertions, 8 deletions

diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index 3d1adad..9c41e71 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -240,15 +240,8 @@ gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 	osrc = 0;
 
 	if (ifp->if_bpf) {
-		/* see comment of other if_foo.c files */
-		struct mbuf m0;
 		u_int32_t af = dst->sa_family;
-
-		m0.m_next = m;
-		m0.m_len = 4;
-		m0.m_data = (char *)⁡
-
-		BPF_MTAP(ifp, &m0);
+		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
 	}
 
 	m->m_flags &= ~(M_BCAST|M_MCAST);